The Influence of Legume Species on the Productivity and Quality of Multi-Species Swards in Four Production Years

In Latvia’s farms, the use of multicomponent grass–legume mixtures is a traditional practice, because swards can secure good persistence and stable productivity. Red clover Trifolium pratense (Tp) and lucerne Medicago sativa (Ms) are traditional forage crops, but fodder galega Galega orientalis (Go) is grown for a relatively short period. Field trials were carried out with the aim to investigate forage yield and quality during four production years of sown legume–grass swards. Mixtures were composed of 50% legumes and 50% grasses (G). Swards were cut three times during the vegetation season. Significant differences in dry matter (DM) yield were found between successive production years and mixture types (MT). Highest DM yield (15.92 Mg ha-1 on average for four production years) was stated for the mixture containing lucerne (Ms+G). The decline in productivity between the first and fourth production years by 14.12 Mg ha-1 (or 68%) was more expressed for red clover mixture (Tp+G), but a more stable productivity was demonstrated by swards containing galega (Go+G) – a yield decrease by 5.88 Mg ha-1 (or 40%). Galega had slow establishment in the sowing year and in the first production year. Galega swards’ productive longevity is one of its main advantages. The mixture containing galega (Go+G) demonstrated the highest crude protein content (CP) in the third and fourth production years. Red clover is a short-term perennial legume, and mixture (Tp+G) had the lowest CP content (99 g kg-1 DM) on average for four production years

The influence of nitrogen fertilization and legume species on the productivity of multi-species swards in four production years

Received: January 27th, 2023 ; Accepted: May 22nd, 2023 ; Published: July 10th, 2023 ; Correspondence: [email protected], [email protected] aim of current research was to investigate forage yield and crude protein content of legume-grass mixtures during four years of sward use, applying three nitrogen (N) fertilisation rates: N0, N60, and N120. Three perennial legume species - red clover Trifolium pratense (Tp), lucerne Medicago sativa (Ms) and fodder galega Galega orientalis (Go) were tested in mixtures with grasses (G). Mixtures were composed of 50% of legumes and 50% of grasses. Lucerne and fodder galega are introduced forage legume species in Latvia, and are raising an ever-growing interest in Latvia. The studies of persistency, quality and yielding ability of these legume species in Latvian agroclimatic condition in comparison with traditionally used red clover are actual. Significant differences in dry matter (DM) yields were found between successive production years, mixtures, and N fertilization rates. The highest average DM yield was found for the mixture with lucerne (Ms+G). The decline in productivity between the first and fourth production years was more expressed for red clover mixture, but a more stable productivity was demonstrated by swards with galega (Go+G). The N rate increase contributed to a significant DM yield increase for all mixtures. The positive effect of the increased N rates on DM yield increase was better expressed for red clover mixture (Tp+G). Red clover mixture (Tp+G) had the lowest average crude protein (CP) content. Mixture with galega had a higher CP content in the third and fourth production years. The CP content of red clover mixtures increased by nitrogen rate

Investigations about the impact of the sowing time and rate of the biomass yield and quality of industrial hemp

ArticleThe aim of this study was to find the optimum sowing rate of industrial hemp (Cannabis sativa L.) and to clarify the impact of the sowing rate on the production of biofuel from hemp biomass in Latvia. Field trials were carried out at the Research and Study Farm ‘Pēterlauki’ of the Latvia University of Agriculture in 2012–2014. The industrial hemp (Cannabis sativa L.) ‘Futura 75’ was sown in a Luvic Endogleyic Stagnosol soil: pHKCl 6.7; P – 52 mg kg-1 ; K – 128 mg kg-1 ; the organic matter content – 21–25 g kg-1 . Hemp was sown in 10-m2 plots, triplicate, on May 8 and 17. The total sowing rate was 20 (100), 30 (150), 40 (200), 50 (250), 60 (300), 70 (350), 80 (400), 90 (450), and 100 (500) kg ha-1 (germinating seeds per 1 m2 ). The plots were fertilised as follows: N – 120 kg ha-1 ; P2O5 – 80 kg ha-1 ; and K2O – 112 kg ha-1 . Hemp was harvested when the first matured seeds appeared. The biometrical indices (height and stem diameter), harvesting time, the amount of fresh and dry biomass, and the fibre content were evaluated. Depending on the sowing rate, the yield of dry matter was on average 9.2–12.1 t ha-1 when hemp was sown at the beginning of May, and 7.9–10.0 t ha-1 when hemp was sown in the middle of May

The efficiency of nitrogen fertilizer on the dry matter yield of tall fescue and festulolium grown as feedstock for combustion

ArticleGrass biomass grows during one vegetation season and can be cultivated and consumed at the place of breeding. Grass biomass can be used not only in traditional feed, but, recently, also for energy production (biogas, solid fuels). The most important economic indicator for any crop is its productivity. The study found that it is important to use nitrogen fertilizer to increase the productivity of tall fescue and festulolium. A significant increase (p < 0.05) in the yield of tall fescue was observed starting from the nitrogen norm of 60 kg ha-1 N. Further increase in nitrogen fertilizer norm provides a significant increase in dry mater yield of tall fescue (reaching 8.64 t ha-1 ) and festulolium (reaching 8.11 t ha-1 ) at 180 kg ha-1 N. The analysis of linear regression coefficients of polynomials showed that the highest nitrogen efficiency in the first year of the use of tall fescue was achieved at the norm of 180 kg ha-1 N, but for festulolium – at the norm of 120 kg ha-1 N. In the following years of tall fescue use, the highest efficiency of nitrogen norms differed: in the 2nd and 4th year of use – at 60 kg ha-1 N, in the 3rd year of use – at 30 kg ha-1 N, and in the 5th year of use – at 120 kg ha-1 N. In contrast, for festulolium, in the 2nd year of use, the highest nitrogen efficiency was reached at the norm of 30 kg ha-1 N, and in the 3rd–5th year of use – at the norm of 60 kg ha-1 N

Производство метана из промышленной конопли

Abstract. Due to the increasing shortage of fossil fuels, the use of alternative energy sources is becoming even more popular. In Latvia, maize is predominantly used for the production of biogas, and other crops are being studied for this purpose. (Research purpose) To study the productivity of industrial hemp varieties (Cannabis sativa L.) and the possibility of obtaining biogas from hemp. (Materials and methods) Field experiments on hemp productivity were carried out on sod calcareous, heavy dusty sand clay soils in 2012-2014. Ten industrial varieties of hemp – 'Bialobrzeskie', 'Futura 75', 'Fedora 17', 'Santhica 27', 'Beniko', 'Ferimon', 'Epsilon 68', 'Tygra', 'Wojko', and 'Uso 31' – were sown with a seeding rate of 50 kilogram per hectare at the background of fertilizers: nitrogen – 120, phosphoric oxide – 90, potassium oxide – 150 kilogram per hectare. Hemp was sown on 10-square meter plots in mid-May, in triplicate. Hemp was harvested at the beginning of seed ripening phase. The whole crop of green mass was calculated on a completely dry matter. The fermentation process for the production of biogas, the average yield of methane, and other parameters were studied in the Laboratory of Bioenergetics of the Latvia University of Life Sciences and Technologies, using small-sized bioreactors. (Results and discussion) The dry matter yield of hemp obtained in the agro-climatic conditions of Latvia averaged 13.32- 17.78 tons per hectare. For an average of three years (2012-2014), higher yields of dry matter were obtained from the varieties of 'Futura 75' (17.76 tons per hectare) and 'Tygra’ (16.31 tons per hectare). The average amount of methane obtained from the 'Uso 31' leaves was 0.365 litre from one gramme of dry organic matter, which is a very good result as compared to other energy crops, for example, corn silage (0.319-0.330 litre from one gramme of dry organic matter in Latvia). (Conclusions) The research has demonstrated that hemp can be successfully used to produce biogas, and hemp leaves are the most suitable starting material.Реферат. Из-за растущей нехватки ископаемого топлива использование альтернативных источников энергии становится все более популярным. В Латвии кукуруза является доминирующей культурой, используемой для производства биогаза, однако ведутся также исследования по использованию других энергокультур. (Цель исследования) Изучить продуктивность сортов промышленной конопли (Cannabis sativa L.) и возжности получения из нее биогаза. (Материалы и методы) Полевые опыты по изучению продуктивности конопли проводили в 2012- 2014 гг. на плодородных дерново-карбонатных, среднетяжелых почвах. Десять промышленных сортов конопли – Bialobrzeskie, Futura 75, Fedora 17, Santhica 27, Beniko, Ferimon, Epsilon 68, Tygra, Wojko и Uso 31 высевали с нормой высева семян 50 килограммов на гектар на фоне удобрений: азота – 120, оксида фосфора – 90, оксида калия – 150 килограммов на гектар. Коноплю сеяли в середине мая, на учетных делянках площадью 10 квадратных метров, в трехкратной повторности. Урожай убирали в начале фазы созревания семян. Всю зеленую массу пересчитали на абсолютно сухое вещество. Процесс брожения для производства биогаза, средний выход метана и другие параметры изучали в лаборатории биоэенеретики Латвийского университета естественных наук и технологий, используя малогабаритные биореакторы. (Результаты и обсуждение) Урожайность сухого вещества конопли, полученного в агроклиматических условиях Латвии, в среднем составила 13,32-17,78 тонны с гектара. В среднем за три года (2012-2014 гг.) более высокие урожаи сухого вещества получили от сортов Futura 75 – 17,76 тонны с гектара и Tygra – 16,31 тонны с гектара. Среднее количество метана, полученного из листьев Uso 31 составило 0,365 литра на грамм сухого органического вещества. Хороший результат по сравнению с другими энергетическими культурами, например кукурузным силосом, показатель которого в Латвии равен 0,319-0,330 литра на грамм сухого органического вещества. (Выводы) Результаты исследований показали, что коноплю, особенно ее листья, с успехом можно использовать для производства биогаза

A hybrid radiation detector for simultaneous spatial and temporal dosimetry

In this feasibility study an organic plastic scintillator is calibrated against ionisation chamber measurements and then embedded in a polymer gel dosimeter to obtain a quasi-4D experimental measurement of a radiation field. This hybrid dosimeter was irradiated with a linear accelerator, with temporal measurements of the dose rate being acquired by the scintillator and spatial measurements acquired with the gel dosimeter. The detectors employed in this work are radiologically equivalent; and we show that neither detector perturbs the intensity of the radiation field of the other. By employing these detectors in concert, spatial and temporal variations in the radiation intensity can now be detected and gel dosimeters can be calibrated for absolute dose from a single irradiation

Dosimetry tools and techniques for IMRT

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98734/1/MPH001313.pd

chromatographic analysis of pharmaceuticals

I,ill,527hal,;28c

Detection of therapeutic radiation in three-dimensions

For over the last twenty years there has been a multitude of sophisticated three-dimensional radiation delivery procedures developed which requires a corresponding verification of the impact on patients. This article reviews the state of the art in the development of chemical detectors used to characterize the three-dimensional shape of therapeutic radiation. These detectors are composed of polyurethane, radical initiator and a leuco dye, which is radiolytically oxidized to a dye absorbing at 630 nm